The What If 100 book is a rundown of What If's most popular episodes. An imaginary adventure through time, space, and chance. The book asks fascinating hypothetical questions and offers up answers that are grounded in scientific theory.

This t-shirt is everything you've dreamed of and more. It feels soft and lightweight, with the right amount of stretch. It's comfortable and flattering for both men and women. • 100% combed and ring-spun cotton (heather colors contain polyester) • Fabric weight: 4.2 oz (142 g/m2) • Pre-shrunk fabric • Shoulder-to-shoulder taping • Side-seamed Size guide XS S M L XL 2XL 3XL 4XL Length (inches) 27 28 29 30 31 32 33 34 Width (inches) 16½ 18 20 22 24 26 28 30

Elevate your style with this unisex eco sweatshirt. The shirt has a chic, crisp look and will go great with both casual and more dressed up outfits. Made of organic and recycled materials, this sweatshirt is durable, comfy, and extra soft. • 85% organic ring-spun combed cotton, 15% recycled polyester • Fabric weight: 350 g/m² (10.3 oz./yd.²) • Regular fit • Set-in sleeves • 1×1 rib at neck collar, sleeve hem, and bottom hem • Single-needle topstitch at neck collar • Double-needle topstitch on the sleeves and bottom hems • Inside herringbone back neck tape • Self-fabric half moon at back neck • Blank product sourced from Bangladesh The sizes correspond to a smaller size in the US market, so US customers should order a size up. This product is made especially for you as soon as you place an order, which is why it takes us a bit longer to deliver it to you. Making products on demand instead of in bulk helps reduce overproduction, so thank you for making thoughtful purchasing decisions!Size guide CHEST WIDTH (inches) BODY LENGTH (inches) SLEEVE LENGTH (inches) S 19⅞ 26¾ 25⅜ M 20⅞ 28⅜ 26 L 22 29⅛ 26 ⅝ XL 23¼ 29⅞ 27⅛ 2XL 24⅜ 30¾ 27¾ CHEST WIDTH (cm) BODY LENGTH (cm) SLEEVE LENGTH (cm) S 50.5 68 64.5 M 53 72 66 L 56 74 67.5 XL 59 76 69 2XL 62 78 70.5

If you’re looking for a thick, structured tee that’s also super soft and breathable—look no further! The men’s garment-dyed heavyweight t-shirt ticks all the boxes and is made of 100% ring-spun cotton. The regular t-shirt style will complement most looks and fit you to a tee. • 100% ring-spun cotton • Fabric weight: 6.1 oz/yd² (206.8 g/m²) • Garment-dyed • Relaxed fit • 7/8′′ double-needle topstitched collar • Twill-taped neck and shoulders for extra durability • Double-needle armhole, sleeve, and bottom hems • Blank product sourced from Honduras This product is made especially for you as soon as you place an order, which is why it takes us a bit longer to deliver it to you. Making products on demand instead of in bulk helps reduce overproduction, so thank you for making thoughtful purchasing decisions! Size guide WIDTH (inches) LENGTH (inches) SLEEVE CENTER BACK (inches) S 18¼ 26 ⅝ 16¼ M 20¼ 28 17¾ L 22 29⅜ 19 XL 24 30¾ 20½ 2XL 26 31 ⅝ 21¾ 3XL 27¾ 32½ 23¼ WIDTH (cm) LENGTH (cm) SLEEVE CENTER BACK (cm) S 46.4 67.6 41.3 M 51.4 71.1 45 L 55.9 74.6 48.3 XL 61 78.1 52 2XL 66 80.3 55.3 3XL 70.5 82.6 59